Colloid cyst

Introduction

Colloid cysts are rare intracranial tumors that are thought to be derived from an endodermal origin and represent 0.3% to 2% of all brain tumors. They account for 0.5% to 2% of all intracranial tumors, typically diagnosed between the fourth and fifth decade of life, and almost always occur in the third ventricle in close proximity to the foramen of Monro, typically at the anterior roof of the third ventricle. These lesions can present with headaches, nausea, vomiting, and some instances of sudden death from obstructive hydrocephalus, whereas a significant percentage present incidentally. The traditional treatment of these lesions has included transcallosal or transcortical craniotomy and resection, but other options include endoscopic resection and tubular retractors with either microscopic or exoscopic visualization. In this chapter, we present a case of a patient with a colloid cyst.

Example case

Chief complaint: headaches and vision changes

History of present illness

A 22-year-old, right-handed woman with a history of attention deficit disorder presented with headaches and vision changes. She was diagnosed with a colloid cyst 4 years prior during a workup for headaches. However, over the past 3 months, her headaches had worsened with complaints of blurry vision. Repeat imaging showed growth of the lesion from 3 to 7 mm ( Fig. 70.1 ).

Medications : Methylphenidate.
Allergies : No known drug allergies.
Past medical and surgical history : Attention deficit disorder.
Family history : No history of intracranial malignancies.
Social history : College student, no smoking, occasional alcohol.
Physical examination : Awake, alert, oriented to person, place, time; Cranial nerves II to XII; No drift, moves all extremities with good strength.
Ophthalmology : Papilledema bilaterally.

	George I. Jallo, MD, Johns Hopkins All Children’s Hospital, St. Petersburg, FL, United States	Basant K. Misra, MBBS, MS, Hinduja National Hospital, V. S. Marg, Mahim, Mumbai, India	Alessandro Olivi, MD, Giuseppe Maria Della Pepa, MD, Fondazione Policlinco Universitario A. Gemelli IRCSS, Catholic University of Rome, Rome, Italy	Gabriel Zada, MD, University of Southern California, Los Angeles, CA, United States
Preoperative
Additional tests requested	Neuroophthalmology evaluation	MRV Neuropsychological assessment	Neuroophthalmology evaluation Neuropsychological assessment	DTI Neuropsychological assessment
Surgical approach selected	Right frontal endoscopic resection	Right pericoronal craniotomy and interhemispheric approach with endoscopic assistance	Right frontal endoscopic resection	Right frontal tubular retractor
Anatomic corridor	Right frontal	Right frontal interhemispheric, transcallosal, transforaminal, transchoroidal	Right frontal	Right frontal
Goal of surgery	Extensive resection, opening of foramen of Monro	Complete removal of cyst	Removal of cyst	Complete cyst removal and opening of foramen of Monro
Perioperative
Positioning	Supine neutral	Supine neutral with 30-degree neck flexion	Supine neutral	Supine neutral
Surgical equipment	Surgical navigation Peel-away catheter Ventricular working-channel endoscope Tissue-biting device	Surgical microscope Endoscope	Ventricular endoscope	Surgical navigation Exoscope Exoscope retractor arm Tubular retractor EVD
Medications	Steroids Antiepileptics	None	Steroids	Steroids Antiepileptics
Anatomic considerations	Fornix, internal cerebral veins, thalamus, thalamostriate veins	Sagittal sinus and draining veins, pericallosal and callosomarginal arteries, corpus callosum, fornix, thalamostriate and septal veins, choroid plexus	Fornix, choroid plexus, septum pellucidum, thalamostriate veins	Fornix, internal cerebral veins, thalamus, thalamostriate veins
Complications feared with approach chosen	Short-term memory deficit, hemorrhage	Seizures, short-term memory deficit, thalamic infarct, pneumoventricle	Short-term memory deficit	Intraventricular hemorrhage
Intraoperative
Anesthesia	General	General	General	General
Skin incision	Linear	Bicoronal curvilinear	Linear	Linear
Bone opening	Right frontal burr hole	Right fronto-parietal parasagittal 2⁄3 in front of coronal suture	Right frontal burr hole	Right frontal
Brain exposure	Right frontal (MFG)	Right frontal	Right frontal (MFG)	Right frontal (MFG)
Method of resection	Burr hole, small corticectomy, introduction of peel-away catheter into lateral ventricle under navigation, introduction of working-channel endoscope, confirm ventricular location, coagulate choroid plexus adjacent to and overlying cyst with monopolar cautery, use side-cutting tissue device to alternate between suction and biting to remove cyst with minimal spillage of cyst contents, attempt gross total resection without damaging fornix, leave EVD	Right pericoronal parasagittal frontoparietal craniotomy 2⁄3 anterior to coronal suture, right dural opening based on sagittal sinus with care to preserve all cortical veins, interhemispheric dissection, identify corpus callosum based on white appearance, 1-cm incision in the corpus callosum either in-between or on the side of both pericallosal arteries, enter ventricle, identify ventricular side based on course of choroid plexus, transforaminal access of cyst, decompress cyst with needle, incise cyst wall, complete cyst decompression with avoiding spillage of contents, develop transchoroidal corridor, complete excision of cyst wall from choroid plexus, endoscope to evaluate for completeness of resection and hemorrhage, copious irrigation, watertight dural closure, subgaleal drain	Burr hole, corticectomy, insertion ventricular endoscope, intraventricular orientation and identification of landmarks, piecemeal excision	Frontal craniotomy, dural opening, confirmation of target, sulcal opening, placement of tubular retractor into ventricle, identification of foramen of Monro and colloid cyst, cauterization of choroid plexus, cyst drainage, dissection from internal cerebral veins, cyst removal, +/– EVD, port withdrawal
Complication avoidance	Endoscope, coagulate choroid plexus, EVD	No sacrifice of cortical veins, transcortical approach if interhemispheric is too narrow, interhemispheric approach, endoscope for inspection making sure complete resection and no intraventricular hemorrhage	Endoscope, piecemeal excision	Tubular retractor, cauterization of choroid plexus, dissection of internal cerebral veins
Postoperative
Admission	ICU	ICU	ICU	ICU
Postoperative complications feared	Short-term memory deficit, hemorrhage	CSF leak, venous infarct, subdural hygroma, hydrocephalus, memory impairment, seizures	Short-term memory deficit, acute hydrocephalus	Hydrocephalus, memory loss, hemiparesis
Follow-up testing	CT immediately after surgery ICP monitoring for 24 hours MRI within 48 hours after surgery	CT within 24 hours after surgery	CT immediately after surgery	MRI within 24 hours after surgery Neuropsychological assessment if needed
Follow-up visits	14 days after surgery, MRI 3 months after surgery	10 days after surgery, MRI 3 months after surgery	10 days after surgery, CT 1 month after surgery, MRI 3 months after surgery	10 days after surgery MRI 3 months after surgery